Re: [PATCH rdma-next 1/1] RDMA/mana_ib: UC QP support for UAPI

[Leon Romanovsky <leon@kernel.org>]

On Thu, Mar 19, 2026 at 03:39:01AM -0700, Konstantin Taranov wrote:
> From: Konstantin Taranov <kotaranov@microsoft.com>
> 
> Implement UC QP creation in the RNIC HW for user API. An UC QP is exposed
> as three work queues: send, receive, and memory management. The latter is
> used for bind and invalidate WQEs to support memory windows.
> 
> Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
> ---
>  drivers/infiniband/hw/mana/main.c    | 41 ++++++++++++-
>  drivers/infiniband/hw/mana/mana_ib.h | 41 ++++++++++++-
>  drivers/infiniband/hw/mana/qp.c      | 92 ++++++++++++++++++++++++++--
>  include/uapi/rdma/mana-abi.h         | 18 ++++++
>  4 files changed, 183 insertions(+), 9 deletions(-)

<...>

> +static int mana_ib_create_uc_qp(struct ib_qp *ibqp, struct ib_pd *ibpd,
> +				struct ib_qp_init_attr *attr, struct ib_udata *udata)
> +{

<...>

> +	if (!udata || udata->inlen < sizeof(ucmd))
> +		return -EINVAL;

<...>

> +	if (udata) {

udata is always true.

> diff --git a/include/uapi/rdma/mana-abi.h b/include/uapi/rdma/mana-abi.h
> index a75bf32b8..a50d4c012 100644
> --- a/include/uapi/rdma/mana-abi.h
> +++ b/include/uapi/rdma/mana-abi.h
> @@ -57,6 +57,24 @@ struct mana_ib_create_rc_qp_resp {
>  	__u32 queue_id[4];
>  };
>  
> +enum {
> +	MANA_UC_UDATA_SQR = 0,
> +	MANA_UC_UDATA_RQR = 1,
> +	MANA_UC_UDATA_SMQ = 2,
> +	MANA_UC_UDATA_MAX = 3,
> +};
> +
> +struct mana_ib_create_uc_qp {
> +	__aligned_u64 queue_buf[MANA_UC_UDATA_MAX];
> +	__u32 queue_size[MANA_UC_UDATA_MAX];

This array is not possible to extend. Any addition to enum above will
break ABI. You shouldn't add enum and use 3 directly here.

> +	__u32 reserved;
> +};
> +
> +struct mana_ib_create_uc_qp_resp {
> +	__u32 queue_id[MANA_UC_UDATA_MAX];

Same.

Thanks

> +	__u32 reserved;
> +};
> +
>  struct mana_ib_create_wq {
>  	__aligned_u64 wq_buf_addr;
>  	__u32 wq_buf_size;
> -- 
> 2.43.0
>